Abstract
The art of passive thermal management lies in effectively mitigating heat stress by manipulating the optical spectra of target objects. However, a significant obstacle remains in finding a structure that can seamlessly adapt to diverse thermal environments. In response to this challenge, we posit that Janus fabrics have unique advantages for multi-scene applications when carefully engineered. A Janus fabric with an upper side exhibiting a 92% solar reflectivity and a 94% emissivity, along with a lower side possessing an infrared emissivity below 30% could enable energy savings at a large scale. It outperforms commercial products in terms of energy-saving efficiency under different climate conditions. Furthermore, the scalable manufacturing compatibility and outstanding performance make the Janus structure a promising avenue for diverse passive thermal management scenarios.